Analytical instruments are well known. They have been commercially used for many years in different constructions and for performing different test analyses by various methods.
In general, these instruments provide for receiving one sample at a time, and more preferably a series of samples, dividing each sample into a plurality of aliquots, and performing one or more tests by combining each aliquot with one or more reagents. The reaction mixtures thus formed are then analyzed in a usual manner. For example, a colorimeter or similar measurement may be made on one reaction mixture. One or more other reaction mixtures may be suspended in a sheath and passed through a flow cell, substantially one particle at a time, and illuminated in the flow cell such that optical interactions can be detected. These interactions may include scatter and absorption of the incident light or a fluorescent response to the incident light. The detected interactions can then be qualitatively and/or quantitatively evaluated to characterize the sample aliquot under examination. The results of the interactions on all of different reactions performed on the sample can be evaluated to characterize the sample.
These instruments typically include numerous hydraulic lines, mixing chambers, valves and control systems to select the samples and reagents to be combined to form the reaction mixtures, and to perform the interactions to collect data. The result is a complicated, sophisticated machine that requires precise timing and fluid controls to process samples in large volumes. One of the problems with these instruments is that, because of their complexity, they may require frequent service, calibration and maintenance. They also are subject to breakdown, which often requires a field service visit. Instruments being out of service until repairs can be made results in significant lost business, particularly in the case of laboratories which perform a large number of test analyses.
It is therefore, an object of the present invention to provide an analytical instrument having improved component construction and operation, which results in fewer parts, fewer service calls, and improved durability and reliability, as compared to the known instruments.
It is another object to provide an improved analytical instrument that is comprised of subcomponents and modules which are applicable to a broad range of analyzer types.